<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>并集选择器</title>
  <style>
    /* div、p、span 文字颜色是红色 */
    div,
    p,
    span {
      color: red;
    }
  </style>
</head>
<body>
  <div>div 标签</div>
  <p>p 标签</p>
  <span>span 标签</span>
</body>
</html>